Method of and apparatus for applying rubber washers to valves or the like



p 3 A. E. BRONSON 1,776,017

IBTH'OD OF AND APPA US F APPLYING RUBBER WAS HE LIKE HERS T0 VES T Filed Dec. 7, 1923 Patented Sept. 16, 1930 UNITED STATES PATENT OFFICE ADELBERT E. BRONSON, OF CLEVELAND, OHIO, ASSIGNOR TO THE DILL MANUFACTUR- ING COIIIPATTY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO METHOD AND APPARATUS FOR APPLYING RUBBER WASHERS TO VALVES OR THE LIKE Application filed December '7, 1923. Serial No. 679,141.

This invention relates to a method of and apparatus for forming an external rubber washer upon a valve member. More particularly the invention relates to valve insides adapted to be detachably mounted within the valve stem of a pneumatic tire and provided with an external rubber washer.

The valve insides commonly employed in the valve stems of pneumatic tires consists of a small tubular member which has a threaded plug portion at its outer end which is adapted to be screwed into an internally threaded valve stem, the tubular member inwardly of the plug having an external conical rubber washer which is forced inwardly against an interior conical seat in the valve stem, and a valve which is adapted to seat against the inner end of the tubular member, the valve having a stem in the form of a rod which extends through the tubular member, the valve being held against its seat by means of a coiled spring surrounding the rod Within the tubular member.

Byreason of the extremely small size of the valve insides, the rubber packing memher or washer upon the outside thereof is necessarily very small and as heretofore made is easily distorted. It ,is therefore very desirable that the rubber packing member or washer be very firmly affixed to the valve insides, otherwise the washer is liable to become distorted resulting in a leaky valve. Unless the washer adheres very firmly to the tubular member it is liable to strip off and remain, when the valve insides is removed, on the valve stem seat.

In methods heretofore employed it has been necessary to slip the rubber washers over the tubular members to the washer seats and the washers have had to be made with suificient elasticity to permit them to stretch over the confining ribs at the end of the seat.

- sure against the entire circumference of the seat so that the rubber firmly adheres to the valve insides throughout the circumference thereof. By molding and vulcanizing the washers directly upon the valve insides, the rubber of the washers is better adapted to retain its shape under pressure.

A further object is to provide a method in which a large number of washers may be simultaneously moulded and vulcanized upon the valve insides.

A further object is to provide a method for molding and vulcanizing the washers directly upon the valve insides.

A further object is to make a more durable and effective washer for valve insides.

With the above and other objects in view, the invention may be said to comprise the method, apparatus and article produced thereby as illustrated in the accompanying drawings hereinafter described and particularly defined in the appended claims, together with such variations and modifications thereof as will be apparent to those skilled in the art to which the invention appertains.

Reference should be had to the accompanying drawings forming a part of this specification in which Figs. 1 and 2 are plan and sectional views. respectively, of the device for perforating a sheet of raw rubber; Figs. 3 and 4 are sectional views showing the mold employed for forming and vulcanizing the washers on the valve insides, Fig. 3 showing the sections separated with the valve insides and sheet of raw rubber in place on the lower section, and Fig. 4 showing the sections clamped together with the washers molded and ready for vulcanizing. Fig. 5 is a bottom view of the upper die.

In accordance with the present invention, the washers are formed directly upon the valve insides from a sheet of raw rubber, the sheet being first perforated at regularly spaced points and placed upon a mold section which supports a series of barrels of valve insides in position such that they will register with the perforations in the sheet of raw rubber so that the sheet may be slipped over the barrels of the valve insides into engagement with the fiat upper face of the mold section. The complementary mold section is formed with openings aligned with the valve insides supported by the lower section and is adapted to be clamped upon the rubber sheet, the rubber willbe forced into the molding chamberyfillingthe same The first section with the flat lower face thereof in engagement with the rubber sheet, the lower portion of the opening in the upper section being formed to provide a washermolding chamber so that when the mold is closed and. pressure is applied to, the raw mold isthen'placed in a vulcanizing press and the rubber, i s-vulcanized while under pressure between the mold sections. causing 'thewashers formed by clamping the mold sections together'to be vulcanized directly upon their seats so that the rubber adheres I firmly to the barrel of the valve insides throughout the circumference thereof. 7

7 Referring to the accompanying drawings,' the rubbersheet perforating device consists of; a suitable flat plate '1 whichhas a series of regularly spaced pins 2 projecting from the upper, face thereof. rubberfis laid upon the top of the pins 2 and is forced down by suitable means upon the surface of the plate 1 causing the sheetto be perforatedv and slightly thickened'aroundeach ofthe perforations. f

The sheet" of raw Thebarrel of the valve insides, is in the -form of a tubular member 4 which hasinner and outer washerretaining ribs 5 and 6, the

"inner rib 5 being tapered on, its inner side and the outer rib 6 being of slightly greater 7 diameter than the rib 5, theribs 5: and 6 the perforatingdevice. v each bore 9 hasa counter-bore 10 of a diameter to receive the enlarged outer end 7 of the 1 tubular member 4, and a second counterbore forming. between'fthem a washer. retaining channel. At its outer end the; tubular member 4 has arslightly enlarged portion 7 T of less diameter than" the rib '6: upon which the threaded plug is adapted to be swiveled.

The lower section8 of themold is in the form of aflat plate which has a series of bores ,9. ltheret hrough which are-positioned in exactly the same'manneras the pins 2 of llis of a diameter to receivethe outer washer.

retaining rib Gjandof a depth to support said rib with its inner face flush with the top face of the section 8. The lower section 8 is adapted to support the tubular members 4 in positions thereof correspondingto the 1 positions of the pins 2 of the perforating j devic'e so that the raw rubber sheet '3 nay J be placed with the perforations in alignment with the upper ends of the tubular members 7 and forced down fiat against an upper face of themold section 8 as shown in Fig. 3..

g 'The upper moldsection 12 is in the form of 'aflat plate provided with bores 13, adapted to-alignwith th'ebores 9 of the lower section,

assu es-0r the bore 13 being such that .therupper.end of the tubular member 4 will I fit thereinfthe lower end of the bore 13 being I enlarged and'provided with a tapered seat 1% adapted to engage the taperedinner side "of At its upper end the washer retaining rib 5, and below'the tapered seat 14 being flared outwardly to provide a washer molding chamber surrounding the washer seat whenvthe sections are clamped together. When the sections are tween the opposed faces ofthe twosections;

and is caused to flowinto the space between the-ribs L 5 and 6 and the flared cavity 15 of the upper mold section, thev rubber be ngv thus molded" into the form of a washer between the ribs 5 and 6 and'tlie flared-cavity 15 surrounding-thetubular inember l. I The; a: mold with the raw rubber molded into thev form of washerssurrounding thevalve'members and held under pressure against the valvemember are then-placed in a suitable Fig. 4: the. rubber sheet is pressed out very moved from the molds after the vulcanizing vulcanizer, and vulcanized. Asv shown 'ina't'b' 1 thin so that when the valve members are reoperation, the vvvalve members with the'waslr:

ers thereon can be readily broken away from '9 vthe sheet. In'practice the valve members with the washers thereon are dumped from the molds into atumbling drum" and then 's "screened entirely free from the thin sheet of rubber connecting the washfersi-nthe; mold. ffiiim li j Having described my inventio nl claim:

1. The process of forming a rubber washer upon avalvejmeinber which comprises applya-body offraw rubber, circumferentially fofa valve'ginember, enclosing thevalvemeni-f ber and confin ng. said body; of rubber be;

tween pressure.mold-members formed to pro vide an annular washer forming chamber around the'valve memberrapplying pressure to said; pressure member to causethe raw rub-i 2'." h ber to flow llltOflIld fill said annular cham-- her, and vulcanizingsaid i'awrubber while held under bers.

pressure between the-mold mem- 2. The. process of forming [a rubber washer? on a valve member'having an, external seat which comprises perforating a sheet of 'raw rubber, inserting the valve member into the;

tions engaging the sheet, applyingpressure to said sheet to cause the rubber to flow into andfill the valve seat, and vulcanizing the rubber-while held under pressure vbetween thef V mold members- The process offormingrubberwashers ing a series of-perforation's'in a sheet of raw rubber, inserting a series of valve members perforation, confining said sheet between pressure applying mold memberswhich have portions enclosingthe'valve member and 1301'- upon a valve member which comprises form-, V

signature.

in said perforations, confining the valve members and sheet between mold members having portions formed to enclose the valve members on opposite sides of the sheet and to provide washer molding cavities surrounding the valve members, and other pressure applying portions adapted to engage opposite faces of the sheet intermediate the valve members, applying pressure to said mold members to 'cause the raw rubber to flow into and fill the washer forming cavities, and vulcanizing the washers on the valve members While held under pressure in the mold.

4:. A mold for use in forming and vulcanizing washers upon valve members comprising f'sections provided with socket portions upon their inner faces adapted to receive the ends of a valve member and providing an annular space surrounding a portion of the valve I member, said sections having inner faces in termediate the socket portions adapted when pressure is exerted on the sections to compress a body of raw rubber and cause the same to flow into and fill annular space around the valve member.

5. A mold for use in forming and vulcanizing rubber Washers upon tubular valve members provided with an external washer receiving channel, comprising a pair of plates each having a series of holes therethrough, one plate aligning with those of the other, the inner ends of the holes in the two plates being formed to receive opposite ends of valve members, and havin shoulders to engage shoulders on the valve members, one of the plates being adapted to support the valve members with the lower edges of the washer channels flush with the top surface thereof, the other of the plates having the inner ends of its openings flared to provide a washer forming chamber around the washer channel on the valve member, the valve member receiving portions of the plates permitting the plates to be moved almost into contact.

In testimony whereof, I hereunto alfix my ADELBERT E. BRONSON. 

